Forging machine



March 9,1926. 1,576,279

, A. T. HOLMAN ET AL FORGING MACHINE Filed May 1. 1924 2 Sheets- Sheet 1Z I! I IHH'H' I jg. F- -"L-q-P J0 19 I i-i- 50 .h. Pg v I 3+ Jig 5145f"a 1 I l El 1 IIHI 1111 1.. i 1

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- mums March 9,1926. 1,576,279

A. T. HOLMAN ET AL FORGING MACHINE Filed May 1. 1924 2 Sheets-Shoot 2Patented Mar. 9, 1926.

UNITED STATES PATENT. OFFICE.

ARTHUR TREVE HOLMAN, 0F CAMBO RNE, CORNWALL, AND KENNETH JAMES HOL- MAN,OF GARBIS BAY, CORNWALL, ENGLAND, LIMITED, OF GAMBORNE, CORNWALL,ENGLAND, ABRITISHUOMPANY;

ASSIG-NORS TO HOLMLAN BROTHERS FORGING MACHINE.

Application filed May 1,

7 '0 all whom it may concern:

Be it known that we, ARTHUR Tnnvn l-IoLMAN and KENNETH JAMES HoLMAN,subjects of the King of England, residingin Camborne, Cornwall, England,and Carbis Bay, Cornwall,- England, have invented certain new and usefulImprovements in Forgspecification.

This invention consists in improvements in or relating to forgingmachines particularly adapted for sh. ing and sharpening the workingfaces of bits for rock-drills and for boring or drilling tools.

One object of the invention is to provide a machine which will combinecompactness with a very considerable holding or gripping pressure forthe drill-bit.

The invention is applied to a known type of machine in which a pair ofjaws is provided one of which is movable by means of apiston-and-cylinder device towards and away from the other." Thedrill-bit or the like is held between these jaws, and a. reciprocatingdolly or forging hammer is provided to operate on the-end face of thebit or the like while it is held between the clamping jaws. There mayalso beassociated with'the jaws a part which'serves to forge or shapeparts of the drill-bit before end-sharpening or shaping is effected bymeans of the dolly;

For the sake of brevity herein machines of this class will be referredto throughout the specification and claims asdrill-sharpening machinesalthough it willbe understood that the machine may be employed for anyforging operation of which such machines are capable.

According. .to one feature of the invention a drill-sharpening machineof the type described is characterized by the combination of the movablejawv with two pistons and cylinders: arranged in tandem,;the pistonsbeing both carried on a' single piston-rod and serving jointly to.actuate the movable jaw to'oloseit on t or towardsits' companion jaw.

The invention also includes other details ofconstruction, all of whichwill be more clearly understood from the following description, given byway of example, of one for the sakeof clearness; ing Machines of whichthe following is a in the several figures 1924. Serial No. 710,326.

vention, which is illustrated in the accompanying drawings whereinFigure 1 is a side elevation of the machine viewed from the left ofFigure 2 with the sizing die and its associated parts omitted Figureflis a section on the line- 22 of Figure 1;

Figure 3 is a section on Figure 1 with a sizing die and holding-meanstherefor shown in position but with the dolly hammer and itsco-operating parts omitted;

and

Figure 4 is an elevationpartly in section of the double jaw. 1 i

Like reference numerals indicate like parts of the drawings.

Ona base or pedestal 10 there are mountpiston-device for the movable .edtwolcylinders Hand 12 co-axially arranged vertically in tandem. WVorkingin the'cylinders-ll and 12 are two pistons 13 and 14; respectively bothmounted on a single piston-rod 15 which slides through the upper wall ofthe cylinderll. The piston l lis'se'cured, to the rod 15 by meansof apin 114 "and the piston 131's held in place by a nut 113. Between thepiston-rod 15 and the orifice in the der 11 through which it slides, areprovided packingaone of which is indicated at 16, so that a fluid-tightfit is afforded andleakage from the upper end of the cylinder'll pastthe piston-rod15 is prevented. g

In order to prevent angular movement of the piston-rod 15, the upperpiston 14, at its lower portion, is formed with projectingwhich arereceved n cor-re side ribs 29 spondingly shaped portions" in the cylinder12, these portions being indicated at 30 in Figurel." g

The piston 14. is 'cut away on opposite sides of a diameter, as shown at17 and 18, to provide flattened surfaces. 'A removable jaw 19 is securedby means of undercut portions 20 and a bolt and retaining washerindicated at 21' in; the piston 11 so that the usual flared end ofthejawis presented in the flat surface of the cut away portion 18. J1companion j aw. 221s similarly secured by undercut portions 23 and abolt, and-reupper wall of the cylinthe line 3' 3 of taining washerindicated at 24 in the upper 7 surface of the top of the cylinder 11,The

jaws 19 and 22, as will be seen from the drawings, are formed withopposed semi cylindricalrecesses (to engage the shank oi a 1dril'1-'bitor the like) which both open into outwardly-flared portions. 1 Y

In addition to the gripping jaw 22 swaging dies 33 are also mounted inthe $0.12 of the cylinder 11 and in piston 14; alongside the grippingjaw. in place by means of plates 3i and bolts 35 which pass completelythrough the thickened upper portion of the cylinder 11 and through theportion 14 respectively in which the dies are mounted. v I

Asizing die 36 is provided and is held 111 position by means of clampingmeans 3 This sizing die is in the form of-agauge-rod the position of theend of'which n relation to the left-hand pair ofswaging dies 33, canbeadjusted to 'determi'nethe diameter of the drill-bit. It willunderstood that the gauge-rod is pushed forward so that its'cnd willengage'the lace of the drill-bit are position along the taper of theswaging dies where the diameter of the dies at that posrtion will bethat reqi'iir'ed for the tool.

The meeting line of the jaws is on alev'el with "the axis ofareciprfocating dolly hammer to which the general reference numeral 25is-applied. This dolly hammer is supported on a bracket 26 in a mannerusual in machines of this sort, spring 27, or a spring oian otherpreferredform and dis- --position, being provided for returning thedolly .to itsinoperative position.

will be seen that when'compressed fluid such as compressed air isadmitted above the pistons 13 and 1 1 they mutually serve to close thejaw 19 on to thej aw22 and in this wav' apply a strong holding pressureto a drill-bit or the like to be held be'tween them. For controlling thesupply of compressed fluid "to the cylinders 11 and 12 a controlvalve,indicated at '28 in Figure 1, is provided but as the operation of thecontrolvalve iswell understod and in itself forms no part of "thepresent invention, it will "not hedescribed in detail "herein, 7

lttda'ptcd to engage the lower end of the 'ais'ton-rofd ltb'utunconnected therewith is a piston 31 which slides in a cylinder 32-130-axially arranged in respect of the cylinders "Hand 12. Inthe cylinder32thereis main tfai'n'ed a *constant airpressure, against which the piston31fis "moved when the jaw 19 is closed onto the-jaw '22. ,This aitords areearn means to when the valve28i's moved to a position in'wliichfi-twill openthe "cylinders 11 and 12 to exhaust.

' newsman that thetop surface or the upper wall of the cylinder '11lis'iormed with a thickened portion, the top surf-ace of The swagingdies are held.

raising'the'pistons 13---and.14

which is shaped to conform to the shape of the opposed end of the piston14.. This is clearly illustrated in Figure3.

Throughout the illustrations the means for securing the parts togetherare omitted, it'orthe sake of clearness, but it will be understoodthatwherever required bolts and nut-s or other securing devices are providedto .aii'ord tight, sound joints between the various portions of thestructure which require to be rigidly attached one to the other.

and two pistons and cylinders the pistons of which are both connected tosaid piston-rod i and serve jointly to more said. movable jaw towardsthecompanion jaw, said pistons being arranged respectively on oppositesides ot the said companion jaw, For the purpose described.

2. A forging machine of the type de scribed comprising in combinationtwo 0pposed work-holding jaws, one at least of which is movablerelatively towards and away from the other, a reciprocating forginghammer arranged to operate: on'the work while it is held bysaidjaws,-:-a"single pistonrod connected with the movable jaw, a pluralityof co axially arranged pistons and cylinders, which pistons arerespectively 0011- nected to said *piston-rodat opposite sides of saidcompaniion jaw and-serve; jointly to move said movable aw in onedirection, and another .plston and cylinder whereof the piston isdisconnected from=the piston-rod and serves to move the latter in adirection reverse to that in which it is moved by the first-mentionedpistons;

3. A forging machine of the type described comprising in combination twoopposed work-holding "jaws one at least of which is movable r'el atively towards and away from the other, a reciprocating forging hammerarranged to operate on the work while it is held by said aws, a; singlepis- WII-TOCl jCOIIIIGCtGCl with the movable jaw, "two pistons andcylinders the pistons of which are respectively connected to saidpiston=rod at opposite sides of said companion jaw and serve jointly tomove said movable jaw towards its-companion jaw, and another piston andcylinder the piston of which is arranged to operate said piston-rod andservesto {return the piston-rod and the movable jaw to the openposition.

"4. A forging machine of the type de scribed comprising in combinationtwo opposed work-holding jaws one at least of which is movablerelatively towards and away from the companion jaw, a reciprocatingforging hammer arranged to operate on the work while it is held by saidjaws, a single piston-rod connected with the movable jaw, two pistonsand cylinders the pistons of which are respectively connected to saidpiston-rod on opposite sides of said companion jaw and serve jointly tomove said movable jaw towards its companion jaw, another piston which isarranged to co act with said piston-rod and serves to return thepiston-rod and tllG'lfiOVEll'JlG jaw to the open position, and a closedair-chamber constituting a cylinder for the last-mentioned piston, andmeans to maintain a permanent air-pressure within said air-chamber, forthe purpose described.

5. A forging machine of the type described comprising in combination twoopposed work-holding jaws one at least of which is movable relativelytowards and away from the other, areciprocating hammer arranged tooperate on the work while it is held by said jaws, a single piston-rodconnected with the movable jaw, and two pistons and cylinders thepistons of which are both connected to the said piston-rod and servejointly to move the said movable jaw towards its companion jaw, the saidpistons being arranged respectively one above and one below the saidcompanion jaw and the upper piston having a cut-back portion to afford aflat on a side wall of the piston for the purpose described.

6. A forging machine of the type described comprising in combination twoopposed work-holding jaws one at least of which is movable relativelytowards and away from the other, a reciprocating forging hammer arrangedto operate onthe work while it is held by said-jaws, a single piston-rodconnected with the movable jaw, and two pistons and cylinders, thepistons of which are both connected to the said piston-rod and servejointly to move the said movable jaw towards the companion jaw and aredisposed respectively above and below the said companion jaw, the latterbeing located in an upper wall of the lowermost of the said twocylinders.

7 A forging machine of the type described comprising in combination two0pposed work-holding jaws one at least of which is movable relativelytowards and away from the other, a reciprocating forging hammer arrangedto operate on the work while it is held by said jaws, a singlepiston-rod connected with the movable jaw, and two pistons and cylindersboth of which pistons are connected to the said piston-rod and servejointly to move said movable jaw towards the companion jaw, the pistonsbeing arranged respectively one aboveand one 'rality of pistons andbelow the companion jaw and the latter'be ing located in an upper wallof the lowermost cylinder, the surface of that wall being shaped toconform to that of the opposed surface of the upper piston.

'8. A forging machine of the type described comprising in combinationtwo opposed work-holding jaws one atleast of which is movablerelativelyrtowards and away from the other, a reciprocating forginghammer arranged to operate on the work while it is held by said jaws, aplucylinders, meansto operatively connect all the said pistons to themovable jaw, laterally projecting ribs formed on at least one of thepistons to afford an unbroken lateral surface and correspondingly shapedrecesses in the cylinderin which that piston works to receive said ribsfor the purpose described.

9. A forging machine comprising in combination a pair of opposedwork-holding jaws one at least of which is movable relatively towardsand away from the'com;

and cylinders the panion jaw, two pistons pistons of which are arrangedrespectively above and below the said companion jaw, a single piston-rodoperatively connected to both said pistons and to said movable jaw, thelatter being located in the lower face of the upper piston, and thecompanion jaw located in an upper wall of the lower cylinder. v 10. Aforging machine comprising in combination two) opposed work-holding jawsone at least of which is movable relatively towards and away from the.other, and a plurality of co-aXially arranged pis tons andcvlinders thepistons of which are all operatively connected to the said movable jawand serve jointly to move it towards the companion jaw, two ofwhich'pistons are respective y situated at opposite sides of the latterjaw.

11. A forging machine comprising in combination two opposed work-holdingjaws one at least of which is movable relatively towards and away fromthe companion jaw, a plurality of co-axially arranged pistons andcylinders the pistons of which are all operatively connected to the saidmovable jaw and serve jointly to move it towards the companion jaw, aco-axially arranged return piston and cylinder, which return piston isarranged to operate said movable jaw and serves to return the latter tothe open position and is situated at the side of the companion jawremote from the movable jaw,

12. Av forging machine of the type described comprising in combinationtwo opposed work-holding jaws one of which at least is movablerelatively towards and away from the companionjaw, a plurality ofco-axially arranged pistons" and cylinpanion jaw.

posed gle connecting rod operatively connected with each said piston andwith-the said movable aw whereby all said plstons serve to move saidmovable aw towards its C0111."

13.7 A forging machine comprising .in combination a pair of work-holdingaws one of which at least is movable towards and away from the companionaw, two coaxially arranged pistons and cylinders the pistons of whichare arranged respectively above and below the said companion jaw, asingle piston-rod operatively connected to both said pistons and to saidmovable jaw, the latter being located in the lower face of theupper-piston and the companion jaw located in an upper wallof the lowercylinder.

14. A forging machine of the type .described comprising in combinationtwo opp work-holding jaws vertically arranged one. above the other, areciprocating .forging hammer arranged to operate on one end-of the workwhile it is held by said jaws, two pistons and cylinders co-axiallyarranged one above the other'with one of the jaws located in an upperface of the lowercylinder and the other jaw located in the lower face ofthe upper piston, a single piston-rod on which both said pistons aremounted, laterally-projecting ribs on} the upper, piston, andcorrespondingly shaped recesses in the outer cylinder to receive saidribs, a third piston at the lower end of said PlStOIl-I'Od, and a thirdCO-(LX131 cylinder for said piston, means to maintain aconstantair-pressure within said. third cylinder, cooperating swaging dies inthe An-THUR TREvE HOLMAN.

KENNETH JAMES HOLMAN.

